BAGHDAD — An American-backed militia that has waged four days of deadly battles to dislodge Islamic State fighters laying siege to a prison in northeast Syria warned on Sunday that the jihadists were using more than 600 boys detained in the complex as “human shields.”
The United States has dispatched attack helicopters and carried out airstrikes on the prison to help the Kurdish-led militia, known as the Syrian Democratic Forces, reassert control. Some of the prisoners were killed in the strikes, U.S. officials said.
American officials defended the attacks.
“The coalition has taken great measures to ensure the humane treatment of detainees, but when ISIS detainees took up arms, they became an active threat, and were subsequently engaged and killed by the S.D.F. and coalition airstrikes,” said Maj. Gen. John W. Brennan Jr., commander of the anti-Isis coalition in Iraq and Syria. The Syrian Democratic Forces are a U.S. partner in the autonomous Rojava region of northeastern Syria.
The coalition said in a statement that it had launched airstrikes and provided intelligence to the Syrian Democratic Forces, which it said had “conducted sustained operations” since the jihadists attacked the prison on Thursday night in a bid to free the ISIS members held there. It said the prisoners had used the prison guards’ own guns to kill some of them after the siege began.
The coalition described the current threat as “contained.”
To try to quell the uprising, a U.S. military official said, Apache helicopter gunships launched airstrikes and conducted low-altitude flights in a show of force.
The siege of the Ghweran prison in Hasaka, where thousands of jihadists and their family members were detained after the collapse of the Islamic State’s so-called caliphate, was well planned.
The commander of the Syrian Democratic Forces, Mazlum Kobani, said ISIS had mobilized sleeper cells and used suicide bombers to organize the breakout.
The fight to retake the prison, the S.D.F. said, was constrained by the militants use of the young detainees as human shields. It said the children were in a special rehabilitation section inside the detention center, which was built as a training college.
“The Syrian Democratic Forces holds ISIS terrorists responsible for causing any harm to these children in prison,” the militia said in a statement.
While the Islamic State trained boys for combat, nicknaming them “cubs of the caliphate,” it is unclear how many of the detained boys had been fighters and how many were in detention simply because they were deemed too old to be in camps for ISIS families.
The Rojava Information Center, which is run by pro-Syrian Kurd activists, said Sunday that while the S.D.F. and Kurdish-led intelligence forces were continuing to tighten the security cordon around the wing of the prison still held by ISIS, they had not yet managed to take back control.
It said 650 of the detainees were under age 18. The children are mostly Syrian, but also include Iraqis and about 150 non-Arab foreigners.
Many of the children were brought to Syria by their parents to live in the caliphate the militants declared in Iraq and Syria in 2014.
Three years ago, with the fall of the last ISIS stronghold, in Baghuz, Syria, many of the children were separated by U.S.-backed security forces from any surviving parents and placed in detention. Others were sent to the prison when they were deemed too old to remain in detention camps for the families of ISIS fighters.
Letta Tayler, associate director of the crisis and conflict division at Human Rights Watch, said she had heard voice messages from a terrified teenager who spoke of seeing bodies and appeared to be in the kitchen part of the prison taken over by ISIS.
“He was saying: ‘There’s a lot of people dead in front of me … I’m scared I might die anytime … I don’t know what to do. Please help me,’” she said.
Ms. Tayler said the boy, a foreigner, reported that the prison was “getting hit from every side.”
Last May, a United Nations human rights report said the conditions under which children were held in northeast Syria meet the threshold for torture, and inhuman and degrading treatment under international law. It described overcrowded conditions, no access to sunlight, malnourishment and untreated injuries.
Ms. Tayler said the crisis happening now could have been averted if the children’s home countries had agreed to repatriate them.
“Detention should be an exceptional measure of last resort,” she said on Twitter. “Instead, foreign countries dumped responsibility for these children on the NE Syrian authorities. If anything happens to these boys during this prison assault, the boys’ home countries will have children’s blood on their hands.”
A propaganda video released by the Islamic State on Sunday showed more than a dozen men identified by the S.D.F. as kitchen workers being held captive by masked ISIS gunmen.
In Iraq, which is also holding its own ISIS detainees and is still battling a persistent jihadist presence, the government has stepped up security at its prisons.
The coalition said it was confident that the attack in Hasaka would not pose a significant threat to Iraq or the region but was still assessing whether the Islamic State was planning any further attacks on detention facilities in Iraq and Syria.
More than 10,000 foreigners, most of them women and children who were the families of ISIS fighters, have been held in squalid and increasingly dangerous detention camps in northeastern Syria since the fall of Baghuz in 2019.
Ben Hubbard contributed reporting from Beirut and Eric Schmitt from Washington.